2. Let children know the structure of two digits, and distinguish between "ten digits" and "unit digits", such as "14", including a "10" and a "4", especially the "1" of ten digits, and understand that it stands for "/kloc-0".
3. The operation of two digits is suitable for the combination of "horizontal" and "vertical". The relationship between vertical ten digits and unit digits is more obvious. Instead of telling these "terms" to children, let them understand them through sensibility.
4. If the child has difficulty in operation, provide small items for the child to juggle and calculate. For example, 14 MINUS 5 is not counted, so let the children take 14 broad beans to assist in the operation. Preschool children are very single-minded, and let them use it when necessary.
The "crutch" of "physical object" helps to improve the computing power.
5. The operation process should be gradual. First practice addition and subtraction without carrying or abdicating within 20 minutes. After thinking it over, carry it forward and abdicate. It is difficult to move and abdicate. Don't worry. When teaching children the addition and subtraction operations within 10, you can often make up some short stories for children to participate in, and children will learn the operation unconsciously. And every time children show great interest in this kind of short story, it is very easy to learn addition and subtraction. For example, learning the addition and subtraction of 8, I made up such a short story, in which I often interacted with children, asked each other questions, and even asked them to make up stories: the little monkey wanted to buy 8 apples for his grandmother. When he came to the market, he saw that the red apple was attractive and the green apple was good, so he bought some of the two apples. Five red apples and several green apples? ) The little monkey walked happily to grandma's house with a box containing eight apples. On the way, I bumped into a pig and knocked off an apple. They don't know. How many apples are left at this time? ) The pig is a good friend of the little monkey. It's good to see a little monkey. When the pig said he was thirsty, the little monkey gave him an apple to quench his thirst. How many apples are left at this time? Seeing the pig eating the apple with relish, the little monkey wanted to eat it, so he took an apple and ate it. How many apples are left at this time? Suddenly, there was a lion's roar behind him: "Ho-"No, the lion saw the little monkey, run! The little monkey ran hard with the box and the apples in the box fell out. Finally, I ran to grandma's house, but the lion didn't catch up. The little monkey finally breathed a sigh of relief. Little monkey apple
The fruit was given to grandma, but grandma looked into the box and said, "ah?" Why are there only two apples left? " Grandma laughed when the little monkey told her what happened on the road. Grandma said to the little monkey, "You are the best gift!" " "In this way, the story is over. In the process of speaking, I also ask my children to count how many apples there are from time to time, and the story of meeting the lion later is also made up by the children themselves. The whole process is very easy, which not only allows children to develop their thinking, but also achieves the purpose of learning.
Recently, some parents have reported that their children's addition and subtraction are not good, and they can't teach them how to teach them. What should teachers do? First of all, I think parents should not worry too much. Children learn mathematics through cognitive process. Just like children learn to walk and talk, they have age characteristics. In large classes, children are only required to master addition and subtraction within ten. But now some parents ask their children to calculate the addition and subtraction within 20, 30 or even 100. I think it is inappropriate, which is no different from "helping seedlings".